1. Field of Invention
This invention relates to a semiconductor device and a method for fabricating the semiconductor device.
2. Description of Related Art
The semiconductor devices in an integrated circuit usually include metal-oxide-semiconductor (MOS) transistors and polysilicon resistors, wherein the gates of the MOS transistors and the polysilicon resistors are usually at the same level.
A method for fabricating such an integrated circuit includes the following steps. After contact openings are formed over the source/drain (S/D) regions, a metal salicide (self-aligned silicide) layer is formed on the S/D regions in the contact openings, and then the contact openings are filled by a metal material to form S/D contacts. M0 metal contacts are then formed to contact the gates of the MOS transistors, the S/D contacts and the polysilicon resistors.
Because a metal salicide layer is not formed on the polysilicon resistors, the M0 metal contacts over the polysilicon resistors directly contact the polysilicon resistors. Thus, the contact sheet resistance between a polysilicon resistor and the corresponding M0 metal contact is large.